In an era when politics has taken a cultural turn, visual propaganda has lost its purpose.

In his review of Milton Glasers's book on socio-political graphics, The Design of Dissent, Nick Gillespie writes that the work catalogued displays "a frustrating and unintentionally revelatory" suggestion of "not only the limits of trendy left-wing politics but arguably of the poster as a political intervention."

A piece of writing on this subject was always going to get my attention. Growing up in Belfast I became aware of visual propaganda very early on. It would have been impossible not to - the gable walls of the city have long been festooned with political propaganda like this.

Today the republican murals expressing armed dissent are mostly gone, replaced with anodyne 'cultural' murals, many of which present a bucolic vision of Irish life that is anathema to someone like myself interested in modernity. Lacking the electoral success of republicans, loyalists have, to a greater degree, continued to create murals darkly celebrating hooded gunmen.

Whatever one makes of these murals they are clearly three things: they are a form of folk art, they are a form of graphic communication and they are a form of propaganda. In comparison to what I was surrounded by in my youth, today's 'activist' graphic design is empty, smug and, frankly, non-political. Let me be clear, I have no wish to romanticise political images and I'm sure most people in Belfast are grateful that images of masked men brandishing Armalites are less common than when I lived in the North of Ireland, but they did tell us something about what was going on in society and of the opposed views that dominated daily life.

A political image today is more likely to chastise the viewer as a naughty consumer rather than make a broad political point. Take a look at any issue of AdBusters if you don't believe me. In which case, the question is not so much Is the political poster powerful? as Does the political poster still exist?

Gillespie's review is in Reason magazine, a journal of which he is editor-in-chief. Reason is unashamedly pro-free-market and as such it is unsurprising that Gillespie comes down hard on left-leaning designers producing images that target corporations. Then again, the relationship between designers and the market economics that spawned them is a curious one, and worthy serious academic study.

Gillespie and I aren't exactly singing from the same political hymn-sheet, but in the case of this review, I think he's got it right. When he quotes Tony Kushner saying "we've seen too often how great design successfully sells monstrous lies" all I can think is that Kushner must think people are idiots. Design is part of selling, to be sure, but to argue that design has sold "monstrous lies" is to entirely remove human agency from the picture. If Kushner is right then the rational actor is reduced to a mere reflexive consumer. Some vision of humanity. If Kushner is right then the murals in Belfast turned ordinary people into machine gun-toting partisans. They didn't. They didn't even turn people into readers of Guns and Ammo magazine.

Gillespie goes on: "A US-based artist mocking American fast food in a high-end Japanese magazine is less an exercise in dissent than the embodiment of smug self-congratulation."